Hepacivirus


Hepacivirus is a genus of positive-sense single-stranded RNA viruses in the family Flaviviridae. The hepatitis C virus, belonging to the species Hepacivirus C, has humans as its only known natural host, and is associated with hepatitis and hepatocellular carcinoma.

Taxonomy

The viruses belonging to this genus have been classified into 14 species - Hepacivirus A-N.
A new virus has been isolated from the bamboo rat while belonging to this genus does not appear to belong to any previously described species.
Another unclassified virus in this taxon is duck hepacivirus-like virus.
A virus in this genus has been isolated from bald eagles
Another virus - Jogalong virus - has been described that appears to belong to another species in this genus.

Structure

Viruses in the genus Hepacivirus are enveloped, with spherical geometries. The diameter is around 50 nm. Genomes are linear and non-segmented, around 10kb in length.
GenusStructureSymmetryCapsidGenomic arrangementGenomic segmentation
HepacivirusIcosahedral-likePseudo T=3EnvelopedLinearMonopartite

Life cycle

Entry into the host cell is achieved by attachment of the viral envelope protein E to host receptors, which mediates clathrin-mediated endocytosis. Replication follows the positive stranded RNA virus replication model. Positive stranded rna virus transcription is the method of transcription. Translation takes place by viral initiation. Human serve as the natural host. Transmission routes are sexual, blood, and contact.
GenusHost detailsTissue tropismEntry detailsRelease detailsReplication siteAssembly siteTransmission
HepacivirusHumansEpithelium: skin; epithelium: kidney; epithelium: intestine; epithelium: testesClathrin-mediated endocytosisSecretionCytoplasmCytoplasmSex; blood

History

Hepatitis C virus, which is the causative agent of hepatitis C in humans, and a member of the species Hepacivirus C, was discovered in 1989. Seven genotypes and eighty six subtypes of hepatitis C virus have been named.
GBV-B virus discovered in 1995 is capable of infecting New World monkeys, in particular tamarins. Like HCV it is transmitted by the blood-borne route and similar to HCV it is associated with the viral hepatitis. However GBV-B has never been identified in wild animals and its natural host is not known.

Additional Information

Additional hepaciviruses have been described from bats, rodents including bank voles, horses and dogs.
Cattle also appear to be a host for viruses belonging to the species Hepacivirus N.
Rodent hepacivirus is found in the deer mouse.
A virus related to hepaciviruses has been isolated from the graceful catshark.
There are at least two subtypes of equine hepacivirus.
The viruses most closely related to Hepacivirus C are the equine hepaciviruses belonging to the species Hepacivirus A.
Hepacivirus A infecting horses has also been found in donkeys.